300D Looks Wierd While Following - PeachParts Mercedes-Benz Forum

MicroRacer · #1 12-27-2003, 10:57 AM

I was following my wife while she was driving our recently acquired Ebay 83 300D. I noticed the car, while driving strait, that more of the left side of the car was showing than the right. I know that that sounds strange, but I don't know how else to explain it.

I have driven the car myself and from the inside I have not noticed anything out of the ordinary. I do know that when I got the car it had 4 spare tires in the trunk and there was pretty severe wear on some of them on the outside of the tires.

Will a misaligned Mercedes track weird or is there something more severe wrong?

engatwork · #2 12-27-2003, 11:06 AM

Come back in 20k miles and tell us what the tires that are on there now look like. Based on your answer at that time can alter my answer but I'll share my initial thoughts. One way to tell if you have a problem now would be to perform a diy'er handling test. You need to try to drive the car in a right and left hand turn, same speed and try to make them as similar as possible. Does the car handle different through one of them versus the other? If there is a difference then yes you have an issue. The rear suspensions on these cars are pretty robust and I imagine you can make the car track down the road in a straight line and the body be slightly "off" but I'm pretty sure you would be able to feel it in driving. I'd start by removing the rear wheels and having a look

for anything obvious. Putting it on a frame straightening machine and getting readings would tell you what is going on for sure.

whunter · #3 12-27-2003, 12:01 PM

What you describe is called dog tracking, an alignment problem.
Could be serious or minor, get a four wheel alignment and be sure you can get a print out of before and after.

Quote:

Originally posted by MicroRacer
I was following my wife while she was driving our recently acquired Ebay 83 300D. I noticed the car, while driving strait, that more of the left side of the car was showing than the right. I know that that sounds strange, but I don't know how else to explain it.

I have driven the car myself and from the inside I have not noticed anything out of the ordinary. I do know that when I got the car it had 4 spare tires in the trunk and there was pretty severe wear on some of them on the outside of the tires.

Will a misaligned Mercedes track weird or is there something more severe wrong?

Have a great day.

psfred · #4 12-27-2003, 01:15 PM

You have to look from the center of the car while behind it to check for "crabbing" -- watch the tires, not the body first, and make sure you know if the front and rear track is the same or not -- car will appear to "crab" badly if the front track (distance between the wheels) is wider on the front than the rear.

An alignment shop is the best way to check.

Things that will cause trouble are bent frames from accidents, bad bushings in the front suspension, notably the track rod bushing (allows the wheel to move backwards), sagging spring in the rear, bad control arm bushings, improper steering wheel or pitman arm/drag link/tie rod setings, or other front wheel alignment problems.

Check your tires for wear -- front end alignment problems can result it serious wear in short order, even though the car "feels" OK. It will feel MUCH better when you get the alighment fixed.

Peter

MicroRacer · #5 12-27-2003, 03:36 PM

Thanks for the suggestions. I will work on it and let you know what I find.

Bill

R Leo · #6 12-27-2003, 05:42 PM

As far as I can tell, as built, W123 chassis do not have any provision for rear wheel alignment.

Consequently, dogtracking will be caused by one or all of the following.

1) really bad subframe bushings
2) bad/worn trailing arm bushings
3) collision damage
4) incorrect spring height (?)
5) binding rear shock(s)

Eccentric trailing arm bushings are available but, to properly set-up the alignment, you'd need access to the MBZ subframe jig to do this. Since there's no post-assembly alignment capabilitites and, having replaced the bushings on one of these cars, I do not think you could 'eyeball' the installation of eccentric bushings and expect any measure of success.

As stated earlier, the subframe in these vehicles is incredibly robust. An impact significant enough to make the car dogtrack will be readily apparent in things like doors not closing properly, obvious creases or impact damage on the trailing arms and or damage to the rear spring towers.

It's possible that incorrect spring height could make the car dogtrack but it seems like you'd notice other issues (car unlevel, etc). And, maybe the same sort of thing could also happen if a bad/damaged shock wasn't allowing the suspension to travel to the proper position.

Lycoming-8 · #7 12-27-2003, 11:47 PM

If you live in an area that will get some snow, you might be able to check out how the car tracks on a nice straight and level street. With the steering wheel placed in center, drive a half a block or so and then go back and see if the rear wheel tracks were in line with the front wheel tracks.

coachgeo · #8 12-27-2003, 11:51 PM

Quote:

Originally posted by Lycoming-8
If you live in an area that will get some snow, you might be able to check out how the car tracks on a nice straight and level street. With the steering wheel placed in center, drive a half a block or so and then go back and see if the rear wheel tracks were in line with the front wheel tracks.

Ive heard the same hint but using mud, beach sand, Sugar, etc.

psfred · #9 12-28-2003, 10:48 AM

R Leo:

Since the rear trailing arms are offset from the centerline, changes in ride height change both camber and toe, so if one side is higher than the other, the car will track one way or the other.

Difference sized tires (or a low one) can do the same thing.

Effect is minor.

Bad trailing arm bushings are VERY noticable -- have one out on the 220D I've never replaced, and it "swoops" terribly in turns,and torque steers like you won't belive.

Peter